<template>
  <div ref="wrapper">
    <slot></slot>
  </div>
</template>

<script>
  import BScroll from "better-scroll";

  export default {
    props: {
      probeType: {
        type: Number,
        default: 1
      },
      click: {
        type: Boolean,
        default: false
      },
      data: {
        type: Array,
        default: null
      },
      refreshDelay: {
        type: Number,
        default: 20
      },
      listenScroll: {
        type: Boolean,
        default: false
      },
      pullup: {
        type: Boolean,
        default: false
      },
      beforeScroll: {
        type: Boolean,
        default: false
      }
    },

    mounted() {
      setTimeout(() => {
        this._initScroll();
      }, 20);
    },

    methods: {
      _initScroll() {
        if (!this.$refs.wrapper) {
          return;
        }
        this.scroll = new BScroll(this.$refs.wrapper, {
          probeType: this.probeType,
          click: this.click
        })

        if (this.listenScroll) {
          this.scroll.on('scroll', (pos) => {
            this.$emit('scroll', pos)
          })
        }

        if (this.pullup) {
          this.scroll.on('scrollEnd', () => {
            if (this.scroll.y <= (this.scroll.maxScrollY + 50)) {
              this.$emit('scrollToEnd')
            }
          })
        }

        if (this.beforeScroll) {
          this.scroll.on('beforeScrollStart', () => {
            this.$emit('beforeScroll')
          })
        }
      },

      enable() {
        this.scroll && this.scroll.enable();
      },
      disable() {
        this.scroll && this.scroll.disable();
      },
      refresh() {
        this.scroll && this.scroll.refresh();
      },
      scrollTo() {
        this.scroll && this.scroll.scrollTo.apply(this.scroll, arguments)
      },
      scrollToElement() {
        this.scroll && this.scroll.scrollToElement.apply(this.scroll, arguments)
      }
    },

    watch: {
      data() {
        setTimeout(() => {
          this.refresh();
        }, this.refreshDelay);
      }
    }
  };
</script>
